JP3508802B2 - Axle bearings for railway vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is, Ru is used in railway vehicle
Those about the bearing axle.

[0002]

2. Description of the Related Art For example, as for a railroad vehicle axle, a conventional double-row cylindrical roller bearing in which a lithium soap compound is used as a thickener and a grease containing mineral oil as a base oil is conventionally used. It had been. However, in recent years, there have been great demands for longer life, higher speed, smaller size around bearing mounting, and further reduction of maintenance cost. To meet these demands, the bearing type is a sealed double row. Tapered roller bearings, so-called RCT bearings, have been developed and have been made smaller and faster.

[0003]

However, the grease adapted to the RCT bearing, that is, the tapered roller bearing, particularly the large brim and the large end face, has a good lubricating performance and is scattered out of the bearing by the centrifugal force accompanying the high speed rotation. Since there is no difficult-to-use grease, longevity and maintenance-free have not been achieved yet. In the Shinkansen axles, double-row cylindrical roller bearings with oil bath lubrication have been used in the past, but as with conventional lines, the RCT is required due to long life, high speed, and maintenance-free requirements.
Although there is a movement to use bearings, because the rotation speed is higher than that of conventional lines, the lubrication conditions for the sliding contact parts of the large end face and large end face of RCT bearings become strict, and bearings filled with conventional grease will be used earlier. It is not possible to meet these demands due to the seizure of the collar part.

Further, there are similar demands for miniaturization, high speed, long life, and maintenance cost reduction for main motors of conventional lines and bullet trains. In these main motors, the occurrence of electrolytic corrosion and the wear of brushes in the case of DC motors have been the factors that determine the life.However, AC motors become the mainstream of the main motors, and the outer diameter of the bearing outer ring is covered by resin. Alternatively, coating of an insulating material such as ceramics has been generally performed in recent years, and the factor that determines the life is the grease sealed in the bearing. The bearing type of the traction motor uses cylindrical roller bearings on the drive side and ball bearings on the opposite side, and mineral oil-based grease with lithium complex soap as a thickener is still commonly used as the encapsulated grease. There are few problems with sliding contact like roller bearings,
Due to the coating of the insulating material, the heat generated during the rotation of the electric motor does not dissipate and the bearing temperature rises, which accelerates the deterioration of the enclosed grease and shortens the life of the bearing. To solve this problem, a grease having a urea compound as a thickener and a synthetic oil as a base oil and improved heat resistance has been developed, but it cannot be used because it is more expensive than conventional greases.

In addition to the above, railcars have bearings used in the drive unit, and conventionally, tapered roller bearings have been used for oil bath lubrication. However, here again, there are the same requirements as above, and bearings and lubrication are also required. There is a movement to change the type to grease lubrication for 4-point contact ball bearings. In this four-point contact ball bearing, so-called differential sliding of rolling elements is large, and conventional greases for axles and traction motors have poor lubrication of sliding portions and cause seizure at an early stage. Further, conventionally, it has been general to add an extreme pressure agent to the grease in order to improve the lubrication of the sliding contact portion. As the extreme pressure agent used for the grease, solid lubricants such as MoS ₂ , sulfur, phosphorus-based, sulfur-phosphorus organic molybdenum,
Compounds such as organic zinc are known. However, all of these compounds have strong chemical activity, and thus have the effect of improving the lubricity of the sliding portion in the short term,
Under a long-term use condition such as a railway vehicle, the bearing may be corroded, the grease may be deteriorated, and seizure may not occur, but smooth rotation tends to be impossible at an early stage. In view of this, the present invention provides a railway vehicle that has higher speed and longer-term reliability than conventional ones by optimizing the enclosed grease.
An object of the present invention is to provide a bearing for an axle .

[0006]

[Means for Solving the Problems] As a result of intensive studies by the present inventors, a specific organometallic compound has an effect as an extreme pressure agent for a long period of time, has a lubricating effect on a sliding contact portion, and It has been found that a bearing that also has an excellent function as an antioxidant and that does not cause the above-mentioned problems and that contains a grease therein can solve the above-mentioned problems, and has completed the present invention. The object of the present invention is to provide a base oil, a thickener,
A bearing for a railroad vehicle axle , which is filled with a grease containing an additive, wherein the additive is a nickel or tellurium alloy.
It is a thiocarbamate, and is 2 to the total amount of grease.
7% by weight, and the base oil has a base oil viscosity of 4 at 40 ° C.
7 to 334 mm ² / s of mineral oil or synthetic hydrocarbon oil
The thickener can be achieved by a bearing for an axle of a railroad vehicle , which is characterized in that the thickener is a urea compound . Further , the object of the present invention is to further add an additive as a model.
Ribden or zinc dithiophosphate at least
1.5 to 3% by weight based on the total amount of grease
Can be achieved by the railway axle bearing of the vehicle, characterized in that it comprises.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Vehicles for railway vehicles according to the present invention
An embodiment of a shaft bearing will be described in detail with reference to the drawings. FIG. 1 shows a wheel support portion 1 of a railway vehicle to which a bearing for a railway vehicle according to the present invention is applied. This wheel support 1
A gear shaft 12 is connected to a rotary shaft 11 of a main electric motor 10 fixed to a vehicle underframe (not shown). Both ends of the gear shaft 12 are supported by tapered roller shafts 13 attached to the vehicle underframe. A small gear 14 is fitted and fixed to the center of the gear shaft 12. Small gear 1
A gear wheel 15 is meshed with the gear 4. This gear 15
Is fitted to the axle 16. Both ends of the axle 16
Two tapered roller bearings 17 mounted on the vehicle underframe,
18 (only one side is shown). Also, axle 1
Wheels 19 are fixed to the outsides of the six tapered roller bearings 17 and 18. Reference numeral 20 in the figure is a deflection plate.

Here, the tapered roller bearings 17 and 18 will be described in detail. These tapered roller bearings 17, 18 are
As shown in FIG. 2, two pieces are used in combination. In each of the tapered roller bearings 17 and 18, a plurality of tapered rollers 23 are rotatably arranged between an outer race 21 and an inner race 22. Tapered roller bearings 17, 1 on both sides
An outer spacer 24 and an inner spacer 25 are interposed between the eight. The outer spacer 24 includes an outer spacer 24 and an inner spacer 25.
A grease injection hole 27 is provided for filling the space 26 between them with grease. The space 26 is filled with grease. As the base oil used for this grease, mineral oil or synthetic hydrocarbon oil can be used, but mineral oil is preferable from the viewpoint of the effect of the extreme pressure agent and the cost. Also,
Base oil viscosity is 47 to 334 mm ² / s (cst)
Is.

[0009] In addition, the thickening agent used in this grease, cormorant rare compounds from the traditional is used. The amount of the thickening agent is not particularly limited as long as the grease property can be obtained, but it is usually 7 to 35% by weight. further,
Additives such as antioxidants, rust preventives, and copper deactivators generally used for greases can be added to this grease. The grease used for the tapered roller bearings 17 and 18 is dithiocarbamic acid of nickel or tellurium.
Salt, particularly preferably dialkyldithiocarbamate
2 to 7% by weight based on the total amount of grease .

In addition, the above-mentioned nickel or tellurium
Dithiocarbamate can be used alone, or
Molybdenum
Cubic acid zinc dithiophosphate (dithiophosphoric acid-based zinc compound
Or a dithiophosphoric acid-based molybdenum compound) is used in combination, the effect is greater than when used alone. Further, by using the dithiophosphoric acid-based molybdenum compound and the dithiophosphoric acid-based zinc compound at the same time, further effects can be obtained. As the dithiophosphonic acid-based zinc compound, zinc diaryldithiophosphate, zinc alkyl-aryldithiophosphate, zinc dialkyldithiophosphate compound and the like can be used, but zinc dialkyldithiophosphate compound is preferable. As the dithiophosphoric acid-based molybdenum compound, molybdenum diaryldithiophosphate, molybdenum alkyl-aryldithiophosphate and molybdenum dialkyldithiophosphate can be used, but molybdenum dialkyldithiophosphate is preferable. Nickel added to the grease enclosed in the tapered roller bearings 17 and 18
Or, the total amount of tellurium dithiocarbamate , alone or in combination , is 2 to 7% by weight of the grease . Addition of more than this has no further effect, and on the contrary, corrosion of the bearing raceway due to chemical action tends to proceed.

Although the same as the above, the grease to be filled in the axle bearing of the railway vehicle of the present invention will be described in more detail below. The grease to be filled in the bearing for the axle of the railway vehicle of the present invention is obtained by blending a thickener and an additive with the base oil. The base oil is mineral oil (paraffinic mineral oil, naphthenic mineral oil, etc.) or synthetic hydrocarbon oil (poly -α- olefin oil, etc.) are used.

[0012] The thickener heat resistance and acoustic properties (especially when used for bearings), leaky, in consideration of heat resistance, di-
Urea compounds such as urea and polyurea are used . The amount of these thickeners is not particularly limited as long as the properties of grease can be obtained, and is approximately 7 to 35 wt% with respect to the base oil.

The grease to be filled in the axle bearing of the railroad vehicle of the present invention is nickel or tellurium dithiocarbamide.
Phosphate, particularly preferably dialkyldithiocarbamine
The acid salt is contained in an amount of 2 to 7% by weight based on the total amount of grease . These dithiocarbamates are considered to have an action of preventing metal contact between the rolling surface and the rolling-sliding surface, but the mechanism is not clear. However, it is considered that when metal contact occurs under boundary lubrication, this compound is decomposed by the heat generated at the contact surface and a protective film is formed on the metal surface which has generated heat. As a result, it is considered that the load bearing property of the rolling-sliding surface and the effect of suppressing heat generation can be obtained.

[0014] The dithiocarbamate may be used alone but the effect of the present invention is obtained, molybdenum or
Zinc dithiophosphate (dithiophosphate zinc compound, dithiophosphate
When these compounds are used in combination, the compounds act catalytically to promote the formation of the above-mentioned protective film, and more effects can be obtained than in the case of using them alone. Furthermore, the combined use of both the dithiophosphoric acid-based zinc compound and the dithiophosphoric acid-based molybdenum compound is most effective. Here, a dithiophosphoric acid zinc compound (ZnDT
As P), zinc diaryldithiophosphate, zinc alkyl-aryldithiophosphate, and zinc dialkyldithiophosphate can be preferably used. Further, as the dithiophosphoric acid-based molybdenum compound (MoDTP), molybdenum dialkyldithiophosphate, molybdenum alkyl-aryldithiophosphate, and molybdenum diaryldithiophosphate can be preferably used. Also, the dithioca
Nickel is also possible as the metal species of lumbamate ,
In this case, a sufficient effect cannot be obtained when used alone, and it is necessary to use at least one of the dithiophosphoric acid zinc compound and the dithiophosphoric acid molybdenum compound in combination.
As the dithiocarbamate of nickel or tellurium, dithiocarbamate nickel (NiDTC) such as nickel dialkyldithiocarbamate, nickel diaryldithiocarbamate, nickel alkyl-aryldithiocarbamate can be preferably used. . Hereinafter, we preferred as additives of the grease sealed in the axle bearing of a railway vehicle of the present invention, T e及 beauty Ni dithiocarbamate (M-DTC: Equation (1)) and Mo
DTP (formula (2)) and ZnDTP (formula (3)) are shown.

[0015]

[Chemical 1]

These additives may be used alone or in combination.
Add 2 to 7 wt% to the total amount of grease . When the amount is less than this, can not be obtained sufficient effect, also more often then further be effective not only can not be expected, conversely proceeds and wear due to chemical action, the durability of the result lubricated parts It may decrease. Also, when used in combination,
The mixing ratio is not particularly limited.

The grease to be enclosed in the bearing for the axle of the railroad vehicle of the present invention contains the above-mentioned base oil, thickener and additive as essential components, but the following additives are added as necessary. May be. In this case, the total amount of addition is 0.1w
t% to 5 wt% is desirable, and if it is less than this, a sufficient effect cannot be obtained, and if it is more than this, the effect does not change, and rather there arises a problem of cost demerit. Metal deactivator: For example, in cylindrical roller bearings and tapered roller bearings, a copper alloy may be used as a retainer material. In order to suppress the corrosiveness of the dithiocarbamate with respect to the copper alloy, a metal deactivator is used. Agents may be added. Specifically, triazole compounds such as benzotriazole and methylbenzotriazole are used. -Rust inhibitor: metal salt of organic sulfonic acid (metal salt of dialkylnaphthalene sulfonic acid, metal salt of alkylbenzene sulfonate, etc .: metal salt is Ca salt, Ba salt, etc.), metal soap (lanolin fatty acid metal salt, wax oxide or wax oxidation) Metal salts of substances: metal salts are Ca, Zn salts, etc.), phosphates or phosphites (dialkyl phosphites, etc.), alkyl succinic acid derivatives (alkyl succinic acid half ester, alkyl succinic anhydride, alkyl succinic acid amide) ), Ester (sorbitan monoalkylate, polyoxyethylene sorbitan monoalkylate, pentaerythritol monoalkylate), amines (rosinamine, N-alkyloylsarcosine) and the like. -Antioxidants: primary antioxidants such as phenylenediamine, diphenylamine, amines such as PANA, nitrogen-containing compounds such as phenothiazine, and hindered phenol compounds are used alone or in combination. If necessary, a phosphorus-based or sulfur-based secondary antioxidant may be added. Oily agent: fatty acid (oleic acid, stearic acid, etc.), aliphatic alcohol (oleyl alcohol), aliphatic ester (polyoxyethylene stearic acid ester, polyglyceryl oleic acid ester), phosphoric acid, phosphoric acid ester (tricresyl phosphate) , Sodium lauryl phosphate, polyoxyethylene oleyl ether phosphate)
etc.

In the above embodiment, the case where the present invention is applied to the tapered roller bearings 17 and 18 has been described. However, the present invention is not limited to this, and the ball bearing 3 shown in FIG.
0, 4-point contact ball bearing 31 shown in FIG.
The present invention can be applied to various types of bearings such as the cylindrical roller bearing 32 shown in FIG. 2 and the double row tapered roller bearing 33 shown in FIG.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. [Examples 1 to 11 and Comparative Examples 1 to 8] Further, using greases having various compositions as shown in Tables 1 to 3, a high-speed durability test by continuous operation under the following conditions, and as shown in FIG. As a result of repeating up-down endurance test by repeating start-up, rotation and stop in various cycles and evaluating the life until seizure, good endurance was confirmed. The 2 columns under Tables 1 to 3 show the test results of the high-speed durability test and the up-down durability test.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

(High-speed durability test) Bearing used: RCT bearing (inner diameter: 130 mm, outer diameter: 20)
8 mm, width: 152 mm), rotation speed: 6000 rpm,
Load: Radial load 3t, Axial load: 1t, Atmospheric temperature: The time until seizure occurred was tested under the conditions of ambient temperature: room temperature. Those that were 1,500 hours or longer were regarded as acceptable products. (Up-down durability test) Bearings used: Cylindrical roller bearings (inner diameter: 85 mm, outer diameter 180)
mm, width 60 mm), radial load: 3 t, axial load: 1 t, and atmospheric temperature: the time until seizure occurred was tested. Goods of 2500 hours or more were accepted.

[0024]

As described above, the railroad vehicle bearing according to the present invention is filled with the grease containing a predetermined amount of a specific organometallic compound as a metal species, and therefore has the effect as an extreme pressure agent for a long period of time. However, the sliding contact part has a lubricating effect and also has an effect as an excellent antioxidant.
It is possible to provide a bearing having high speed and long-term reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing a wheel supporting portion to which a bearing for a railway vehicle according to the present invention is applied.

FIG. 2 is a detailed view of a tapered roller bearing.

FIG. 3 is a sectional view showing various bearings to which the present invention is applied.

FIG. 4 is a diagram showing a cycle of an up-down durability test.

[Explanation of symbols]

1 wheel support 10 Main motor 11 rotation axis 13, 17, 18 tapered roller bearings 16 axles 19 wheels 30 ball bearings 31 4-point contact ball bearing 32 Cylindrical roller bearing 33 Double Row Tapered Roller Bearing

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C10M 107: 02 C10M 115: 08 115: 08 135: 18 135: 18 137: 10 A 137: 10) C10N 10:04 C10N 10: 04 10:12 10:12 10:16 10:16 20:02 20:02 30:06 30:06 30:10 30:10 40:02 40:02 50:10 50:10 (56) References Japanese Unexamined Patent Publication No. 6-25688 (JP, A) Japanese Unexamined Patent Publication No. 6-88085 (JP, A) Japanese Unexamined Patent Publication No. 57-55997 (JP, A) International Publication 95/19411 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B61F 17/30-17/34 C10M 101/02 C10M 105/02-105/06 C10M 107/02-107/18 C10M 115/08 C10M 129/26-129/66 C10M 135 / 10 C10M 135/18 C10M 135/36 C10M 137/10 C10M 141/10 C10M 169/00-169/06 C10N 10:02-10:04 C10N 10:12 C10N 10:16 C10N 20:02 C10N 30:06 C10N 30:10 C10N 40:02 C10N 50:10

Claims (2)

(57) [Claims] 1. A bearing for an axle of a railway vehicle , in which a grease containing a base oil, a thickener and an additive is enclosed, wherein the additive is nickel or tellurium dithiocarbamic acid.
It is a salt and contains 2 to 7 wt% of the total grease.
And the base oil has a base oil viscosity at 40 ° C. of 47 to 334 mm.
² / s of mineral oil or synthetic hydrocarbon oil,
Railway vehicle characterized in that the filler is a urea compound
Axle bearings. 2. Further, as an additive, molybdenum or
Uses at least one zinc dithiophosphate.
The bearing for an axle of a railway vehicle according to claim 1, which is contained in an amount of 1.5 to 3% by weight based on the total amount of lease .